Need advice on minimum requirements to enable legal hold on data from legacy mailboxes in Exch Online under plan 2

There's (hearsay) ambiguity about the length of time for which one has to maintain (pay for) Exchange Online P2 subscriptions applied to legacy mailboxes migrated from an on-premise archiving solution to the cloud (O365).

The mailboxes are no longer used, but the data needs to be retained for a period of time for legal purposes.

I believe that I can subscribe to Exch Onl P2 for the period required until migration and legal hold enablement are completed, then cancel the subscriptions. A colleague suspects we need to retain the subscriptions for a minimum of three months before being allowed to retain the data indefinitely.

Is there a three-month minimum threshold based on your experience under similar circumstances?

Nope, my LAR and Microsoft seem uncertain, but not confident either way.

2answers

Answers

The above are two useful articles. The account goes inactive once a leaver leaves, so all licenses are removed. The mail is still stored though. If there is a legal challenge, then an EXO2 license can be used to review the emails as part of the legal hold piece.

Quite frankly, it is a massive grey area as we're not sure either. Haven't had to do so in anger yet, but it is something that needs clarification.

There is no grey area as to whether it can be done - putting a legacy mailbox on hold and then reassigning the license is perfectly fine.

If a user leaves my company, and I need to retain a copy of the data in their mailbox and In-Place Archive, what are my options?

You can retain the data in that user’s mailbox by placing the user on In-Place Hold and marking the mailbox as inactive. It isn’t necessary to maintain a user subscription license for the inactive mailbox.